Spark plug



5, I R. PALAZZOLO 1,990,347

SPARK PLUG Original Filed Oct. 20, 1932 INVENTOR POM/6V0 /D/4LA 22040 fl/ 1 ATTORNEYS Patented. Feb. 5, 1935 I L "PATENT OFFICE;

' I Application October 20, 1932, Serial No. 638,703 Renewed June: 25, 1934- 3 Claims. (01. 123-169) This invention relates to improvements in spark plugs.

The primary object of the invention resides in a'means for protecting the electrode end of a spark plug against the accumulation of carbon deposit during use of the spark plug in the cylinder of an internal combustion engine.

Another feature of the invention is to provide a shield 'or protector attachment for the electrode end of a spark plugto lessen the accumulation of carbon thereon and prevent fouling of the spark plug by the oil of an internal combustion engine. This attachment thus avoids the frequent removal of the spark plug from the engine cylinder for cleaning purposes, and serves to increase the life of the spark plug.

A further object of the invention is to provide a spark plug protector which shields the electrode end of the plug without in any way interfering with the direct contact of the gases of combustion with the spark gap. After becoming heated during use, the attachment serves to preheat the gases of combustion about the electrode, thus assuring a more efficient combustion of the gases resulting in a higher efiiciency of power.

A still further object is to provide a spark plug protector having the above features which is simple of construction and inexpensive of manufacture.

With these and other objects in View, the invention resides in the certain novel construction, combination and arrangement of parts, the essential features of which are hereinafter fully described, are particularly pointed out in the appended claims, and are illustrated in the accompanying drawing, in which:

Figurel is a side elevational view of my improved spark plug.

Referring to the drawing by reference charv acters, the numeral 10 designates a spark plug of the conventional construction in that it includes a chambered body or shell 11, formed with a lower reduced externally screw threaded extension 12, and beyond which the spaced electrodes 13 extend.

Diametrically opposite sides of the threaded extension 12 are slots or recesses as at 14 which form shoulders 15 at the top thereof. It will be seen that flattening or recessing opposite sides of the threaded extension the screw threads of the same are not continuous, but this does not interfere with the screwing of the plug into the threaded hole of an engine cylinder.

My electrode protector comprises a substantially U-shaped member 16 constructed of a single length of flat metal which includes a bight portionl'l and opposed leg portions 18. The side edges of the legportions 18 are disposed in upwardly converging relation to reduce the width at the top of the U-shaped member, while the flattened surfaces 14 of the spark plug are correspondingly shaped. Diametrically opposed openings 19 are provided in the leg portions 18 and when the U-shaped member is positioned upon the threaded extension of the spark plug with the portions 18 fitting against the flat surfaces 14 of the spark plug, the said openings 19 register with threaded openings 20 in the threaded extension 12. The inner walls of the threaded extension 12 adjacent the openings 20 are thickened or provided with bosses 21 to enable screws 22 to freely pass through the openings 19 and threadedly engage the walls of the threaded openings 20.

When the U-shaped protector is in position upon the spark plug, the top ends of the legs 18 abut the shoulders 18 and the recesses or cut away portions 17 are of sufficient depth that the side edges of the legs 18 are short of the circumferential plane of the threads of the threaded extension 12. This is necessary in order that the legs 18 of the attachment will in no way interfere with the threading of the plug into position-within the threaded opening in an internal combustion engine cylinder.

With the attachment 16 in positionupon the spark plug, it will be observed that the bight portion .17 overlies the open bottom end of the plug and is disposed in spaced relation with respect to the electrodes 13, while opposite sides of the plug are open adjacent the electrodes to enable the gases of combustion to come in contact with the spark produced by the electrodes 13 during operation of the plug. The protector member 16 will shield the electrode end of the spark plug to lessen the accumulation of carbon upon the electrode and the surrounding portion of the plug and will also prevent direct contact of the electrode with oil from the engine. By the use of this protector attachment, the life of a spark plug may be prolonged and the frequent removal of the spark plug from the engine cylinder is avoided as the electrode end will be kept clean and fre- While I have shown and described what I deem, to be the most desirable embodiment of my in" vention, I wish it to be understood that (such changes as come within the scope .of myappended claims may be resorted to if desired. 1

Having thus described the invention, what 11 claim as new and desire to-secure by Letters Patent of the United States, is:-

1. In a spark plug having a bodyexternally screw threaded at one end andan electrode at the threaded end,,oppos ed sides of the threaded-portion of the body being flattened, a substantially U-shaped protector member having its opposed sides fitting against the flattened sides of said body and in spaced relationto the electrode, the

edges of the sides of said protector member being .clearof the circumferential plane of the threads toenable free screwing of the threaded .end of said body into the threaded opening of an internal combustion engine cylinder, and means for securing said protector member to said body.

2. In a spark plug having a body externally screw threaded at 'oneend, an electrode at the threaded end, opposed sides-of the threaded portion of the body being flattened, substantially U-shaped protector member having its opposed sides fitting against'the flattened sides of said body and in spaced'relation to the electrode, the edges of the sides of saidpr'otector memberbeing clearof the circumferential plane of the threads to enable free screwing of %thethreaded end of said body into the'threaded opening of an internal "combustion enginecylinder, and screws passing through the sides of said protector member and v threaded into threaded openings provided in the flat portion of said body;

3. A spark plug having a chambered body exrternally screw threaded at one end andelectrodes extending from the chambered body beyond the plane of the threaded end thereof, flat sur faces provided on opposed outer sides of the threaded portion of thechambered body,-a sub-' stantially U-shaped protector member having :a bight portion and opposed leg portions, theleg portions embracing the :flattened sidesof said chambered body, while thebight portion overlies .the open chambered end of said body in spaced relation to said electrode, .and removable fasten: ing elements passing through said legs and threaded into said ,body for securing said U- shaped member thereto. I

.RosARI'o :PALAZZOLO, 

